This document contains questions about seismic refraction and reflection techniques. A normal moveout correction is applied to common midpoint gathers before stacking. A synthetic seismogram is generated by convolving an acoustic impedance log with an input pulse. It provides a relationship between travel times and depth to interfaces. Seismic velocity generally increases with depth due to increasing bulk and shear modulus with depth.
This document contains information about an EOS 350 midterm exam, including 23 multiple choice questions and 5 short answer questions. It provides equations that may be useful for the exam, describes the question format and point values, and lists the multiple choice and short answer exam questions.
Name ______________________ Class _________________ Date .docxrosemarybdodson23141
Name: ______________________ Class: _________________ Date: _________ ID: D
1
Exam 1
1. The moment magnitude scale depends on
a. the rupture area, slip magnitude, and shear
rigidity of rock
b. the length of the fault
c. the depth of the earthquake
d. the amplitude of shaking
2. The particle motions of P-waves
a. are perpendicular to the wave propagation
direction.
b. are retrograde elliptical.
c. are horizontal.
d. are compression only.
e. involve dilations and compressions in
direction of wave propagation.
3. Which of the following statements is TRUE
about plate boundaries and their earthquakes?
a. Divergent plate boundaries produce very large
earthquakes, transform boundaries produce
small events, and convergent boundaries
produce large-to-intermediate sized
earthquakes.
b. Divergent boundaries produce small to
moderate sized earthquakes, transform
boundaries produce moderate to large
earthquakes, and convergent boundaries
produce the largest earthquakes.
c. Divergent boundaries are rare but they do
produce the largest events.
d. Convergent boundaries and transform
boundaries both produce the magnitude 9.0
events in equal numbers.
4. A magnitude 6.0 earthquake will affect the largest
area of shaking in which region below?
a. Northeast United States
b. California along the San Andreas Fault
c. In the state of Nevada in the western United
States
d. In the state of Utah in the western United
States
5. The intraplate earthquakes in New Madrid,
Missouri in 1811 and 1812
a. where very small and not felt widely.
b. were larger than magnitude 7.0, felt as far
away as Boston, and occurred in a failed rift
zone.
c. occurred where the Pacific and North
American plates meet.
d. were not as large as magnitude 7.0, with felt
shaking confined mainly to the regions of the
midwestern United States.
6. The enormous earthquake of March 11, 2011 in
Japan was greater than 9.0 because
a. it occurred on a major transform fault zone.
b. it occurred on a major normal fault in a
divergent plate boundary zone.
c. slip occurred on a large area of fault patch
with a slip of one centimeter.
d. slip occurred on a large area of fault patch
with a large amount of slip of as much as half
a football field (50 meters)
7. Which of the following will most likely lead to a
Natural Disaster?
a. A magnitude 3.0 earthquake beneath New
York City
b. A magnitude 8.0 very far from any populated
region
c. A magnitude 7.5 with an epicenter 10
kilometers from downtown Tokyo
d. An earthquake with a maximum felt intensity
of V
e. An earthquake at a mid-ocean ridge
8. An earthquake initiates at 35°N, 108° W, and
depth Z = 10 km. What is its epicenter?
a. 10 km
b. 35° N
c. 35° N, 108° W
d. 108° W
e. the waves that radiate from the source
Name: ______________________ ID: D
2
9. An example of the presently active early stages
of continental rifting can be found in
a. Mid continent of North America
b. East Africa
c. Indi.
This document provides an ultrasonic testing level 2 exam with 40 multiple choice questions covering topics like surface waves, transducer types, testing methods, and interpreting scan results. It tests knowledge of longitudinal and shear wave propagation, factors that affect attenuation, near and far field zones, and using calibration standards. The questions cover topics like pulse-echo testing, immersion testing, interpreting A-scans and B-scans, and identifying discontinuities based on scan presentations.
Seismic methods use seismic waves created by impacts on the surface to map underground structures. The waves travel through underground layers and are reflected or refracted at boundaries between different materials. Analysis of the travel times and velocities of the waves allows determining the depth and type of geological layers. Seismic reflection techniques involve creating waves at shot points and recording them with receivers at different offsets to generate common midpoint gathers. Processing the gathers yields a seismic section that images layer boundaries like an echo sounder. Seismic refraction uses refracted head waves along interfaces to build a shallow velocity model for near-surface layers. Both methods together provide structural and physical characterization of underground features like buried valleys.
The document contains a practice test for a physical science exam with 40 multiple choice questions covering topics like the four strokes of an engine, plane mirror images, wave properties, electromagnetic radiation, electric charge, hydrocarbons, metal properties, forces, chemical reactions, gravitational potential energy, lunar eclipses, mineral properties, pressure in fluid streams, magnetism produced by electricity, momentum, machine efficiency, forms of energy, acceleration due to gravity, moon's gravity, circuit power, water pollution, electromagnetic waves, momentum after collision, echo minimization, volcano features, phonograph needle speed, fish density, identifying alkenes and alkanes, re
This document provides an overview of gravity and seismic geophysical exploration methods. It begins with introductions to gravity, its units of measurement, and factors that cause gravity variations. It then discusses gravity data acquisition, processing steps like tidal and elevation corrections to derive anomaly maps, and interpretation. For seismic exploration, it describes data acquisition using common midpoint gathers and factors like fold, followed by processing steps like normal moveout correction and stacking to improve signal-to-noise ratio and imaging resolutions. It concludes with discussions on filtering, migration, and how these improve subsurface representations.
The document contains 23 multi-part questions related to wave properties and behavior. The questions cover topics such as calculating wave properties like wavelength, phase speed and particle motion from given parameters; estimating wave properties at different depths and under the influence of currents; applying wave theories to problems involving wave propagation over varying bathymetry; and analyzing wave loads on coastal structures. Sample questions provided seek solutions for wave characteristics at offshore measurement locations, during propagation to shore, and at breaking.
The document contains a 30 question summative test on concepts in seismology. It covers topics like the different types of seismic waves (P, S, and surface waves), their properties and motions, using triangulation to determine an earthquake's epicenter by measuring the arrival times of seismic waves at multiple stations, and calculating seismic wave speeds. The test aims to assess understanding of key seismological concepts and methods used in earthquake analysis.
This document contains information about an EOS 350 midterm exam, including 23 multiple choice questions and 5 short answer questions. It provides equations that may be useful for the exam, describes the question format and point values, and lists the multiple choice and short answer exam questions.
Name ______________________ Class _________________ Date .docxrosemarybdodson23141
Name: ______________________ Class: _________________ Date: _________ ID: D
1
Exam 1
1. The moment magnitude scale depends on
a. the rupture area, slip magnitude, and shear
rigidity of rock
b. the length of the fault
c. the depth of the earthquake
d. the amplitude of shaking
2. The particle motions of P-waves
a. are perpendicular to the wave propagation
direction.
b. are retrograde elliptical.
c. are horizontal.
d. are compression only.
e. involve dilations and compressions in
direction of wave propagation.
3. Which of the following statements is TRUE
about plate boundaries and their earthquakes?
a. Divergent plate boundaries produce very large
earthquakes, transform boundaries produce
small events, and convergent boundaries
produce large-to-intermediate sized
earthquakes.
b. Divergent boundaries produce small to
moderate sized earthquakes, transform
boundaries produce moderate to large
earthquakes, and convergent boundaries
produce the largest earthquakes.
c. Divergent boundaries are rare but they do
produce the largest events.
d. Convergent boundaries and transform
boundaries both produce the magnitude 9.0
events in equal numbers.
4. A magnitude 6.0 earthquake will affect the largest
area of shaking in which region below?
a. Northeast United States
b. California along the San Andreas Fault
c. In the state of Nevada in the western United
States
d. In the state of Utah in the western United
States
5. The intraplate earthquakes in New Madrid,
Missouri in 1811 and 1812
a. where very small and not felt widely.
b. were larger than magnitude 7.0, felt as far
away as Boston, and occurred in a failed rift
zone.
c. occurred where the Pacific and North
American plates meet.
d. were not as large as magnitude 7.0, with felt
shaking confined mainly to the regions of the
midwestern United States.
6. The enormous earthquake of March 11, 2011 in
Japan was greater than 9.0 because
a. it occurred on a major transform fault zone.
b. it occurred on a major normal fault in a
divergent plate boundary zone.
c. slip occurred on a large area of fault patch
with a slip of one centimeter.
d. slip occurred on a large area of fault patch
with a large amount of slip of as much as half
a football field (50 meters)
7. Which of the following will most likely lead to a
Natural Disaster?
a. A magnitude 3.0 earthquake beneath New
York City
b. A magnitude 8.0 very far from any populated
region
c. A magnitude 7.5 with an epicenter 10
kilometers from downtown Tokyo
d. An earthquake with a maximum felt intensity
of V
e. An earthquake at a mid-ocean ridge
8. An earthquake initiates at 35°N, 108° W, and
depth Z = 10 km. What is its epicenter?
a. 10 km
b. 35° N
c. 35° N, 108° W
d. 108° W
e. the waves that radiate from the source
Name: ______________________ ID: D
2
9. An example of the presently active early stages
of continental rifting can be found in
a. Mid continent of North America
b. East Africa
c. Indi.
This document provides an ultrasonic testing level 2 exam with 40 multiple choice questions covering topics like surface waves, transducer types, testing methods, and interpreting scan results. It tests knowledge of longitudinal and shear wave propagation, factors that affect attenuation, near and far field zones, and using calibration standards. The questions cover topics like pulse-echo testing, immersion testing, interpreting A-scans and B-scans, and identifying discontinuities based on scan presentations.
Seismic methods use seismic waves created by impacts on the surface to map underground structures. The waves travel through underground layers and are reflected or refracted at boundaries between different materials. Analysis of the travel times and velocities of the waves allows determining the depth and type of geological layers. Seismic reflection techniques involve creating waves at shot points and recording them with receivers at different offsets to generate common midpoint gathers. Processing the gathers yields a seismic section that images layer boundaries like an echo sounder. Seismic refraction uses refracted head waves along interfaces to build a shallow velocity model for near-surface layers. Both methods together provide structural and physical characterization of underground features like buried valleys.
The document contains a practice test for a physical science exam with 40 multiple choice questions covering topics like the four strokes of an engine, plane mirror images, wave properties, electromagnetic radiation, electric charge, hydrocarbons, metal properties, forces, chemical reactions, gravitational potential energy, lunar eclipses, mineral properties, pressure in fluid streams, magnetism produced by electricity, momentum, machine efficiency, forms of energy, acceleration due to gravity, moon's gravity, circuit power, water pollution, electromagnetic waves, momentum after collision, echo minimization, volcano features, phonograph needle speed, fish density, identifying alkenes and alkanes, re
This document provides an overview of gravity and seismic geophysical exploration methods. It begins with introductions to gravity, its units of measurement, and factors that cause gravity variations. It then discusses gravity data acquisition, processing steps like tidal and elevation corrections to derive anomaly maps, and interpretation. For seismic exploration, it describes data acquisition using common midpoint gathers and factors like fold, followed by processing steps like normal moveout correction and stacking to improve signal-to-noise ratio and imaging resolutions. It concludes with discussions on filtering, migration, and how these improve subsurface representations.
The document contains 23 multi-part questions related to wave properties and behavior. The questions cover topics such as calculating wave properties like wavelength, phase speed and particle motion from given parameters; estimating wave properties at different depths and under the influence of currents; applying wave theories to problems involving wave propagation over varying bathymetry; and analyzing wave loads on coastal structures. Sample questions provided seek solutions for wave characteristics at offshore measurement locations, during propagation to shore, and at breaking.
The document contains a 30 question summative test on concepts in seismology. It covers topics like the different types of seismic waves (P, S, and surface waves), their properties and motions, using triangulation to determine an earthquake's epicenter by measuring the arrival times of seismic waves at multiple stations, and calculating seismic wave speeds. The test aims to assess understanding of key seismological concepts and methods used in earthquake analysis.
The document discusses waves used for communication and evidence for the expanding universe. It covers electromagnetic waves, sound waves, and mechanical waves. It also discusses how different types of waves are used for communication like radio, microwaves, infrared and visible light. Finally, it discusses how the observed red-shift of distant galaxies provides evidence that the universe is expanding, supporting the Big Bang theory of the universe beginning from a very small initial point.
The document summarizes research on using seismic methods to detect and characterize a sinkhole in Doha, Qatar. A seismic survey was conducted along the edge of the sinkhole opening. The recorded seismic data revealed a distinct resonance peak at 70 Hz above the sinkhole. Numerical modeling showed that this peak is indicative of a karst side wall separating rock, karst border, and roof. The data were inverted in the frequency domain and fit using a model with low velocity and density parameters in the sinkhole layer, representing the complex geometry of karst.
This paper presents a joint analysis of surface wave and microgravity surveys to estimate S-wave velocity and density models of the subsurface. Surface wave testing and microgravity surveys were conducted along a 205m survey line to map a buried channel filled with soft sediments. An S-wave velocity model was derived from surface wave data using cross-correlation analysis. Gravity data was then analyzed based on the S-wave model, converting it to a density model using soil properties. A least squares method was used to modify the density model to reduce residuals between calculated and observed gravity, resulting in a clear low-density area matching the low S-wave velocity channel.
This document discusses borehole shear-wave surveys, which measure shear wave velocities in soil and rock layers. Shear wave velocities provide more information about material properties than P-wave velocities alone. The document describes conducting cross-hole and down-hole surveys using a surface hammer source to generate shear waves, which are detected by geophones in boreholes. Proper field techniques and data analysis are outlined to accurately measure shear wave velocities with depth. The velocities are used to characterize materials and calculate elastic properties important for foundation and seismic design.
This document describes an extension of the SRICOS method for predicting scour depth at bridge piers. The extended method, called E-SRICOS, accounts for variable flow velocities over time (velocity-time histories) and multilayer soil stratigraphy. It accumulates the effects of different velocities and sequences through soil layers to predict scour depth. The document outlines the E-SRICOS algorithms and procedures. It also presents a simplified version, S-SRICOS, and compares predictions of both methods to measurements at eight bridge sites in Texas.
1) A spacecraft measures the redshift of photons emitted from the surface of a star to determine the star's mass M and radius R. As it approaches the star, it measures the velocity needed for resonant absorption of photons by He+ ions.
2) The experimental data gives the velocity needed for resonance at different distances from the star. This data is plotted to determine M and R graphically.
3) In addition to gravitational redshift, the emitted photons will experience a small relativistic frequency shift due to the recoil of the emitting atom. This effect is much smaller than the gravitational redshift.
This document provides 6 problems related to electromagnetism for assignment help. It addresses topics like polarization, Fresnel's formulas, electromagnetic waves in plasma, skin effect, group velocity, and surface electromagnetic waves. It gives the questions, outlines the approach and key steps to solve each problem, and provides the solutions. The document aims to help students with assignments on electromagnetic theory and related concepts in electromagnetism.
This document contains 43 physics questions about waves, including:
1. Questions about the wavelength, frequency, and speed of various wave types like sound waves, electromagnetic waves, and water waves.
2. Questions about wave phenomena like the Doppler effect, diffraction, polarization, and stationary waves.
3. Diagrams of waves and oscilloscope traces that ask about the frequency, amplitude, or other characteristics of the waves.
This document contains a long quiz with 20 multiple choice questions about waves and their properties. The questions cover topics like wavelength, amplitude, frequency, speed, energy transfer, types of waves including mechanical, electromagnetic, transverse and longitudinal waves. Sample questions are asked about wave speed given wavelength and frequency, energy transfer of pulses along strings, properties that waves have in common or independently, and types of waves like sound, light, water and seismic waves.
This document provides an overview of ultrasonic testing concepts and terminology. It covers topics such as determining wavelength from velocity and frequency, dispersion of sound in materials, thickness resonance, calibration of testing equipment, types of ultrasonic waves, factors that affect velocity, attenuation of sound, transducer types, testing methods like through transmission and immersion, and displays like A-scans and B-scans. It also contains multiple choice questions to test understanding of these concepts.
This document provides information about wave properties and behavior. It defines key wave terms like amplitude, wavelength, frequency, speed, and wavefront. It describes the differences between transverse and longitudinal waves, giving examples of each type. It explains how ripple tank experiments can demonstrate the reflection and refraction of water waves at boundaries where speed changes. Reflection causes a change in wave direction while preserving other properties. Refraction is caused by a change in speed, causing a change in wavelength and direction but preserving frequency. Sound wave reflection and refraction are also described.
The document is about sample physics questions for an entrance exam for admission to BSc Agriculture programs in Tamil Nadu Agricultural University and other agricultural universities. It contains 33 multiple choice physics questions on topics like mechanics, electricity, waves, optics and thermodynamics along with explanations for the answers. The questions are provided in both English and Tamil.
This document provides an overview of electromagnetic waves and key concepts in physics including:
- James Clerk Maxwell showed that electric and magnetic fields can form propagating electromagnetic waves.
- Electromagnetic waves include visible light, ultraviolet rays, infrared rays, radio waves, x-rays and gamma rays.
- The speed of electromagnetic waves in a vacuum is a constant at approximately 3×10^8 m/s.
- Electromagnetic waves transport energy and the total energy density carried by a wave depends on the electric and magnetic field amplitudes.
This document defines various terms used in geophysics and related fields. It provides definitions for terms such as E (the SI prefix for 1018), eccentricity (the ratio of the focus-to-center distance to the length of the semimajor axis for an ellipse), and earthquake (a sudden movement of the earth resulting from the abrupt release of accumulated strain, usually a result of faulting or volcanism). The document also includes brief descriptions of concepts like Earth layering, earthquake seismology, and eigenfunctions.
1) Geophysics uses remote sensing to determine subsurface conditions by analyzing seismic and radar signals that travel through and reflect off underground materials.
2) There are four main modes of signal propagation: vertical reflection, wide angle reflection, critical refraction, and direct waves. Precisely measuring the travel times of these signals allows subsurface structures to be interpreted.
3) Reflection seismology analyzes reflected signals to determine depth to interfaces by relating travel time, distance between source and receiver, and velocity, while refraction seismology uses travel times of critically refracted signals to determine shallow subsurface velocity structure.
Crosshole Seismic Reflection: Coal Mine FieldsAli Osman Öncel
The document summarizes research on using crosshole seismic reflection methods for opencast coal exploration. Small explosive charges are used as sources in one borehole, while hydrophones in a nearby borehole record seismic reflections. This provides high-resolution seismic sections between boreholes. Results from two UK coal sites image coal seams and detect small faults not seen with sparser surface exploration methods. While velocity modeling is challenging, the method can locate hazards for excavation and improve reserve estimates compared to traditional borehole spacing.
The document discusses various concepts related to waves including:
1. The amplitude of a wave is inversely proportional to its distance from the source. When amplitude doubles, distance halves.
2. Resonance frequencies of an open organ pipe are calculated based on quarter and three quarter wavelengths.
3. For three different waves, the ratios of their frequencies and wavelengths are given.
4. The detection of waves depends on the number of compressions and rarefactions detected per unit time.
5. Malus' law describes how the intensity of polarized light emerging from polarizers depends on the angle between their polarization axes.
The document is the first page of a 2 page engineering geology exam containing 5 questions. It includes multiple choice and true/false questions about topics like rock layers, mineral properties, and river systems. It also includes short answer questions requiring calculations related to river discharge, rock outcrop dimensions, aquifer properties, and a topographic map profile.
Optics tutorial 1st year physics classes 2013-2014 { Problems n Solutions}QahtannRose
1. This document discusses several optics concepts including: the behavior of light passing through openings of different diameters, how light travels from distant galaxies, calculating the speed and wavelength of light in different media using Snell's law and the refractive index, calculating angles of reflection and refraction, types of waves, and more. Maxwell's equations predict electromagnetic waves that propagate through space at the speed of light.
1) The document analyzes the impact of a proposed new coal-fired power plant in Lakhra, Pakistan on the existing southern Pakistan power system through power flow and transient stability analyses.
2) Power flow analysis found no overloading or voltage violations with or without the new Lakhra plant under normal and N-1 contingency conditions.
3) Transient stability analysis found the system became unstable for some single circuit fault cases when the Lakhra plant was included, but remained stable without the Lakhra plant. The analyses aim to examine if system reinforcement is needed with the new Lakhra plant.
This document provides an online manual for the G2010 series printer that covers:
- Basic operation instructions for printing, copying, scanning, and handling paper, originals, and ink tanks
- Maintenance procedures like cleaning the print head and print quality troubleshooting
- Safety and handling precautions for transporting and disposing of the printer
- Descriptions of the printer's main components including the operation panel, power supply, and LCD display
- Instructions for changing printer settings from a computer or the operation panel
The document discusses waves used for communication and evidence for the expanding universe. It covers electromagnetic waves, sound waves, and mechanical waves. It also discusses how different types of waves are used for communication like radio, microwaves, infrared and visible light. Finally, it discusses how the observed red-shift of distant galaxies provides evidence that the universe is expanding, supporting the Big Bang theory of the universe beginning from a very small initial point.
The document summarizes research on using seismic methods to detect and characterize a sinkhole in Doha, Qatar. A seismic survey was conducted along the edge of the sinkhole opening. The recorded seismic data revealed a distinct resonance peak at 70 Hz above the sinkhole. Numerical modeling showed that this peak is indicative of a karst side wall separating rock, karst border, and roof. The data were inverted in the frequency domain and fit using a model with low velocity and density parameters in the sinkhole layer, representing the complex geometry of karst.
This paper presents a joint analysis of surface wave and microgravity surveys to estimate S-wave velocity and density models of the subsurface. Surface wave testing and microgravity surveys were conducted along a 205m survey line to map a buried channel filled with soft sediments. An S-wave velocity model was derived from surface wave data using cross-correlation analysis. Gravity data was then analyzed based on the S-wave model, converting it to a density model using soil properties. A least squares method was used to modify the density model to reduce residuals between calculated and observed gravity, resulting in a clear low-density area matching the low S-wave velocity channel.
This document discusses borehole shear-wave surveys, which measure shear wave velocities in soil and rock layers. Shear wave velocities provide more information about material properties than P-wave velocities alone. The document describes conducting cross-hole and down-hole surveys using a surface hammer source to generate shear waves, which are detected by geophones in boreholes. Proper field techniques and data analysis are outlined to accurately measure shear wave velocities with depth. The velocities are used to characterize materials and calculate elastic properties important for foundation and seismic design.
This document describes an extension of the SRICOS method for predicting scour depth at bridge piers. The extended method, called E-SRICOS, accounts for variable flow velocities over time (velocity-time histories) and multilayer soil stratigraphy. It accumulates the effects of different velocities and sequences through soil layers to predict scour depth. The document outlines the E-SRICOS algorithms and procedures. It also presents a simplified version, S-SRICOS, and compares predictions of both methods to measurements at eight bridge sites in Texas.
1) A spacecraft measures the redshift of photons emitted from the surface of a star to determine the star's mass M and radius R. As it approaches the star, it measures the velocity needed for resonant absorption of photons by He+ ions.
2) The experimental data gives the velocity needed for resonance at different distances from the star. This data is plotted to determine M and R graphically.
3) In addition to gravitational redshift, the emitted photons will experience a small relativistic frequency shift due to the recoil of the emitting atom. This effect is much smaller than the gravitational redshift.
This document provides 6 problems related to electromagnetism for assignment help. It addresses topics like polarization, Fresnel's formulas, electromagnetic waves in plasma, skin effect, group velocity, and surface electromagnetic waves. It gives the questions, outlines the approach and key steps to solve each problem, and provides the solutions. The document aims to help students with assignments on electromagnetic theory and related concepts in electromagnetism.
This document contains 43 physics questions about waves, including:
1. Questions about the wavelength, frequency, and speed of various wave types like sound waves, electromagnetic waves, and water waves.
2. Questions about wave phenomena like the Doppler effect, diffraction, polarization, and stationary waves.
3. Diagrams of waves and oscilloscope traces that ask about the frequency, amplitude, or other characteristics of the waves.
This document contains a long quiz with 20 multiple choice questions about waves and their properties. The questions cover topics like wavelength, amplitude, frequency, speed, energy transfer, types of waves including mechanical, electromagnetic, transverse and longitudinal waves. Sample questions are asked about wave speed given wavelength and frequency, energy transfer of pulses along strings, properties that waves have in common or independently, and types of waves like sound, light, water and seismic waves.
This document provides an overview of ultrasonic testing concepts and terminology. It covers topics such as determining wavelength from velocity and frequency, dispersion of sound in materials, thickness resonance, calibration of testing equipment, types of ultrasonic waves, factors that affect velocity, attenuation of sound, transducer types, testing methods like through transmission and immersion, and displays like A-scans and B-scans. It also contains multiple choice questions to test understanding of these concepts.
This document provides information about wave properties and behavior. It defines key wave terms like amplitude, wavelength, frequency, speed, and wavefront. It describes the differences between transverse and longitudinal waves, giving examples of each type. It explains how ripple tank experiments can demonstrate the reflection and refraction of water waves at boundaries where speed changes. Reflection causes a change in wave direction while preserving other properties. Refraction is caused by a change in speed, causing a change in wavelength and direction but preserving frequency. Sound wave reflection and refraction are also described.
The document is about sample physics questions for an entrance exam for admission to BSc Agriculture programs in Tamil Nadu Agricultural University and other agricultural universities. It contains 33 multiple choice physics questions on topics like mechanics, electricity, waves, optics and thermodynamics along with explanations for the answers. The questions are provided in both English and Tamil.
This document provides an overview of electromagnetic waves and key concepts in physics including:
- James Clerk Maxwell showed that electric and magnetic fields can form propagating electromagnetic waves.
- Electromagnetic waves include visible light, ultraviolet rays, infrared rays, radio waves, x-rays and gamma rays.
- The speed of electromagnetic waves in a vacuum is a constant at approximately 3×10^8 m/s.
- Electromagnetic waves transport energy and the total energy density carried by a wave depends on the electric and magnetic field amplitudes.
This document defines various terms used in geophysics and related fields. It provides definitions for terms such as E (the SI prefix for 1018), eccentricity (the ratio of the focus-to-center distance to the length of the semimajor axis for an ellipse), and earthquake (a sudden movement of the earth resulting from the abrupt release of accumulated strain, usually a result of faulting or volcanism). The document also includes brief descriptions of concepts like Earth layering, earthquake seismology, and eigenfunctions.
1) Geophysics uses remote sensing to determine subsurface conditions by analyzing seismic and radar signals that travel through and reflect off underground materials.
2) There are four main modes of signal propagation: vertical reflection, wide angle reflection, critical refraction, and direct waves. Precisely measuring the travel times of these signals allows subsurface structures to be interpreted.
3) Reflection seismology analyzes reflected signals to determine depth to interfaces by relating travel time, distance between source and receiver, and velocity, while refraction seismology uses travel times of critically refracted signals to determine shallow subsurface velocity structure.
Crosshole Seismic Reflection: Coal Mine FieldsAli Osman Öncel
The document summarizes research on using crosshole seismic reflection methods for opencast coal exploration. Small explosive charges are used as sources in one borehole, while hydrophones in a nearby borehole record seismic reflections. This provides high-resolution seismic sections between boreholes. Results from two UK coal sites image coal seams and detect small faults not seen with sparser surface exploration methods. While velocity modeling is challenging, the method can locate hazards for excavation and improve reserve estimates compared to traditional borehole spacing.
The document discusses various concepts related to waves including:
1. The amplitude of a wave is inversely proportional to its distance from the source. When amplitude doubles, distance halves.
2. Resonance frequencies of an open organ pipe are calculated based on quarter and three quarter wavelengths.
3. For three different waves, the ratios of their frequencies and wavelengths are given.
4. The detection of waves depends on the number of compressions and rarefactions detected per unit time.
5. Malus' law describes how the intensity of polarized light emerging from polarizers depends on the angle between their polarization axes.
The document is the first page of a 2 page engineering geology exam containing 5 questions. It includes multiple choice and true/false questions about topics like rock layers, mineral properties, and river systems. It also includes short answer questions requiring calculations related to river discharge, rock outcrop dimensions, aquifer properties, and a topographic map profile.
Optics tutorial 1st year physics classes 2013-2014 { Problems n Solutions}QahtannRose
1. This document discusses several optics concepts including: the behavior of light passing through openings of different diameters, how light travels from distant galaxies, calculating the speed and wavelength of light in different media using Snell's law and the refractive index, calculating angles of reflection and refraction, types of waves, and more. Maxwell's equations predict electromagnetic waves that propagate through space at the speed of light.
1) The document analyzes the impact of a proposed new coal-fired power plant in Lakhra, Pakistan on the existing southern Pakistan power system through power flow and transient stability analyses.
2) Power flow analysis found no overloading or voltage violations with or without the new Lakhra plant under normal and N-1 contingency conditions.
3) Transient stability analysis found the system became unstable for some single circuit fault cases when the Lakhra plant was included, but remained stable without the Lakhra plant. The analyses aim to examine if system reinforcement is needed with the new Lakhra plant.
This document provides an online manual for the G2010 series printer that covers:
- Basic operation instructions for printing, copying, scanning, and handling paper, originals, and ink tanks
- Maintenance procedures like cleaning the print head and print quality troubleshooting
- Safety and handling precautions for transporting and disposing of the printer
- Descriptions of the printer's main components including the operation panel, power supply, and LCD display
- Instructions for changing printer settings from a computer or the operation panel
1. The document discusses electrical submersible pumps (ESPs), which are pumps used to lift fluid out of wells. An ESP has a hermetically sealed motor attached directly to the pump body, allowing the entire assembly to be submerged.
2. ESPs work by using an impeller and diffuser to convert the rotational energy of the motor into kinetic and pressure energy in the fluid. The impeller spins and adds energy to the fluid, while the stationary diffuser converts this energy into fluid pressure.
3. The main components of an ESP system are the downhole components of the motor, seal, pump and cable, as well as the surface components of transformers, motor controllers, and a junction box
This document discusses vertical lift relationships and working charts used to determine production parameters like PWF given other known values. It provides an example of using a working chart for a 1.5" tubing to calculate a PWF of 1600 psi given a PTH of 200 psi, flow rate of 500 bbl/day, well depth of 5000 ft, and GLR of 200 scf/bbl. It also demonstrates using vertical flow performance curves and an IPR curve to determine an allowable flow rate of 820 bbl/day at a PWF of 1450 psi.
- Wiggins proposed generalized correlations to predict the inflow performance relationship (IPR) during three-phase flow, similar to Vogel's method. The correlations allow estimating future maximum flow rates as a function of current and future average reservoir pressures.
- Standing's method extends Vogel's method to predict future IPR as a function of declining reservoir pressure. It introduces the productivity index J and defines the current zero drawdown productivity index Jp. Standing's method estimates a future productivity index Jf to generate the predicted future IPR.
- An example applies Standing's method to predict the future IPR for a well producing from a saturated reservoir when reservoir pressure declines from 4000 psi to 3000 psi. It calculates Jp
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Seismic_for_students.pdf
1. Questions: Seismic Refraction and Reflection
1. Before stacking reflection seismic data, a normal move-out correction is applied.
This correction is applied to data that is sorted in
a. common shot gathers
b. common receiver gathers
c. common midpoint gathers
d. common offset gathers
2. A synthetic seismogram is generated by from an acoustic impedance log by
a. convolving it with an input pulse
b. determining the density of each layer
c. determining the seismic velocities of each layer
d. generating a reflection coefficient log and convolving it with an input
pulse
3. A synthetic seismogram is important for interpreting reflection seismic data
because it provides a relationship between
a. travel times and depth to interfaces
b. density and seismic velocity
c. layer thicknesses and travel times
d. density and depth to interfaces
4. Within a given sedimentary layer, a change in the p-wave acoustic impedance
could indicate a change in
a. Porosity
b. Pore fluid content
c. Lithification
d. All of the above
5. In marine seismic exploration, a seismic source such as an air gun or water gun is
used to generate seismic energy. All seismic sources deployed in the water have
what feature in common?
a. They generate P-waves only
b. They generate S-waves only
c. They generate both P and S waves
d. They generate both P and SV waves
6. In order to determine the velocity of a layer using refraction seismic, we need at
least two geophones with first arrivals from that interface to _____________ for
that event on the T-X plot.
a. Account for noise
b. Compute the slope
c. Determine the offset distance
d. Compute the critical angle
2. 7. Typically, seismic velocity increases with depth. The main reason for this is that,
in general, ____________________ with depth
a. Density increases
b. Bulk and shear modulus increase
c. Bulk and shear modulus increase more rapidly than density
d. Density increases more rapidly than bulk and shear modulus
8. For a reflection seismic survey, where the subsurface has an average P-wave
velocity of 1000m/s and we use a 10ms seismic wavelet, the best resolution we
could obtain is?
a. 1 m
b. 2.5 m
c. 5m
d. 10 m
9. Seismic migration can be best described as
a. Converting the seismic section from time to depth
b. Adjusting the reflection time based on the hyperbolic travel time
c. Stacking the traces
d. Putting seismic reflectors in their correct location
10. A refraction seismic survey is conducted in a region with a planar, dipping layer
beneath a flat overburden layer. The surface is flat. The velocity of each layer is
constant, and v1< v2<v3. Do you expect the reciprocal times from the dipping
interface to match?
a. No, because the forward and reverse shots travel along different ray paths
b. Only if there is no noise in the data
c. Yes, because the forward and reverse shots travel along the same ray path
d. No, because the velocity in the up-dip direction is greater than in the
down-dip direction
11. A refraction seismic survey is conducted in a region with a planar, dipping layer,
with γ = 1°. The velocity in layer 1 is 400 m/s, and the velocity of the second
layer is 2000 m/s. Which of the following pairs of up and down dip velocities
could be observed
a. vu = 2105 m/s , vd = 1910 m/s
b. vu = 1910 m/s , vd = 2105 m/s
c. vu = 2000 m/s , vd = 1900 m/s
d. vu = 1900 m/s , vd = 2000 m/s
12. In a seismic survey, an air wave can be best described as
a. A wave that travels through the air
b. A compression wave that travels through the air in the pore spaces in the
rock
3. c. A direct, compression wave that travels from the source to the geophones
through the air
d. All of the above
13. A seismic survey is conducted in a region with two layers. The top layer is shale,
with density 2500 kg/m3
, and seismic velocity of 2900m/s, and the bottom layer is
sandstone, with a density of 2100 kg/m3
, and a seismic velocity of 3000m/s. The
reflection coefficient will be
a. Positive
b. Negative
c. Zero
d. Not enough information
14. A seismic survey is set-up with a source in a borehole, 100m below the surface,
and an array of geophones on the surface. There is an interface at 200m. The top
layer has velocity 1000m/s and the lower layer has velocity 2000m/s. Which of
the following characteristics on a T-X plot will remain the same if the source was
now moved to the surface?
a. Slope of the refracted arrivals
b. Intercept times of the refracted arrivals
c. Arrival times of the direct ray
d. Arrival times of the reflections
15. When looking at first arrival times in a seismic refraction survey, what
relationship between the layer velocities allow us to determine the velocity of
layer 3 and know that it is in fact the velocity for layer 3?
a. V1 < V2 < V3
b. V2 < V1 < V3
c. as long as V2 > V3
d. V1>V2<V3
16. When considering the critical angle for V1 > V2, what of the following is true?
a. We can calculate the critical angle using Snell’s law
b. The critical angle in this case is calculated by another method
c. We need some more information to compute critical angle
d. There is no critical refraction
17. Which of the following statements about Snell’s law in the context of a seismic
survey is incorrect?
Here, θ1 is the incidence angle and θ2 is the transmission angle.
a. Snell’s law shows the angular relationship between the incident and
transmitted waves at the interface in terms of velocities
b. The angle of reflection can be different from the angle of incidence
4. c. When a seismic wave travels from a region of low velocity to high velocity,
the wave is refracted away from the normal vector of the interface
d. When θ2=90 degree, a head wave develops due to critical refraction
18. Which of these elastic moduli describes the ratio between volumetric stress and
volumetric strain?
a. Young’s Modulus
b. Shear Modulus
c. Bulk Modulus
d. Poisson’s Ratio
19. A compressional wave…
a. Is also called an S-wave.
b. Can travel only through solids.
c. Depends on density, shear modulus, and bulk modulus.
d. All of the above
20. In which of the following geoscience problems is a seismic refraction survey most
likely to provide valuable information?
a. geological mapping of British Columbia
b. oil and gas exploration in the Gulf of Mexico
c. locate a near surface pipeline outside EOS East Building
d. geotechnical study for the site of the new earth system science building of
UBC
21. Which geological model would lead to a failure of refraction survey?
a. more than two layers overlying the basement
b. dipping or irregular interface
c. seismic wave travels faster in the surface layer than in any other layer
d. all of above
22. Reciprocal times are total travel times from the
a. first geophone to the last geophone of a spread
b. first geophone to the last geophone of a reverse spread
c. shot of forward spread to the shot location of reverse spread
d. shot to the last geophone of a spread
5. 23. If the incident angle is 45 degrees and the seismic velocity in the first medium is a
reasonable value for sediments, and the seismic velocity in the second medium is
4 times slower than in the first medium, then the refracted angle
a. Is less than 45 degrees.
b. Is more than 45 degrees.
c. Is 45 degrees.
d. Cannot be determined given this information.
24. Suppose a seismic refraction survey was conducted over an area with 3 horizontal
layers (ie 2 interfaces). Which of the following scenarios would produce first
arrivals at surface geophones from all three layers? (Top layer: seismic velocity
v1, middle layer: seismic velocity v2, lower layer: seismic velocity v3)
a. V1 = 400 m/s, v2 = 2000 m/s, v3 = 1500 m/s
b. V1 = 1500 m/s, v2 = 2000 m/s, v3 = 400 m/s
c. V1 = 2000 m/s, v2 = 1500 m/s, v3 = 400 m/s
d. V1 = 400 m/s, v2 = 1500 m/s, v3 = 2000 m/s
25. Suppose the correct scenario was found for the above question, for a refracted ray
path traveling along the second interface (between the middle and lower layer),
what is its incident angle at the first interface (between the top and middle layer)?
a. Sin-1
(v2/v3)
b. Sin-1
(v1/v3)
c. Sin-1
(v1/v2)
d. Sin-1
(v2/v1)
26. Assume that the earth is represented by a horizontal layer overlying a half-space.
A simplest refraction survey with minimum instrument requires
a. one shot and one geophone
b. one shot and two geophones
c. one shot and three geophones
d. two shots with two geophones
27. Dave carried out a single-shot seismic refraction survey to find the depth to the
basement and the velocity structure. Exact knowledge about the material above
the basement and the shape of the basement interface was not known. After
carrying out the survey he picked out the first arrivals and plotted the T-X graph
6. as below. What conclusion can Dave make?
a. he can only see one refraction so there is only one layer overlaying the
basement
b. he can determine the velocity of the basement by measuring the slope of
the dashed line
c. he can estimate the critical angle using the intercept time of the refraction
arrival
d. none of the above
28. In a seismic reflection survey each trace in the processed section
a. Is the signal that would be received if the source and receiver were
coincident
b. Is the measured signal from the geophone that is closest to the receiver
c. Is the signal from the common offset array
d. Is the signal from a common midpoint array
29. The acoustic impedance of a medium
a. is equal to the value of the seismic velocity
b. depends upon the product of density and velocity
c. depends upon the ratio of density and velocity
d. depends upon velocity and bulk modulus
30. “Seismic reflections can occur when only when there is a change in seismic
velocity”. (This is a Right – Wrong question for a final mark. Correct gets one
mark; wrong loses a mark)
a. TRUE
b. FALSE
7. 31. How does the seismic method differ from the magnetic method?
a. Seismic is sensitive to density changes while magnetics is sensitive to
magnetic susceptibility
b. The magnetic method is a natural source field while seismic method can
use either an artificial or a natural source
c. Collecting seismic measurement requires contact with the ground while
collecting magnetic data can be done at the surface or airborne.
d. All of the above
32. Acoustic impedance is used to describe the efficiency of seismic reflection and
transmission. Its value depends upon
a. critical angle and velocity
b. velocity and density
c. reflection and transmission coefficients
d. layer thickness and velocity
33. Which of the following is the most important first step in the sequence of
processing seismic refraction data?
a. Choosing whether arrivals are direct or refracted.
b. Picking first breaks from raw seismic traces.
c. Guessing seismic velocities of expected materials.
d. Transferring arrival times to a TX graph.
34. A ray path is passing through the interface between Layer 1 and Layer 2 with
incident angle 45 degree. Suppose the velocity of Layer 1 is 500m/s, what is the
velocity of Layer 2 if we expect a critical refraction on the interface?
a. 850m/s
b. 250m/s
c. 707m/s
d. 354m/s
35. Please order the common materials below according to their seismic velocity
a. air > sediments > sandstone> granite
b. granite > sandstone > sediments > air
c. granite > sediments > sandstone > air
d. air > sediments > granite > sandstone
36. What is a possible physical reason for the increase in slope of this TX graph?
8. a. There may be a low velocity layer that is detectible with refraction data.
b. The dip of a refracting horizon steepens half way along the portion
observed by the survey
c. The first two segments of the graph are both direct arrivals.
d. The thickness of the overlying layer decreases with distance.
37. Why is a NMO (normal moveout) correction applied to reflections in a CMP
gather?
a. To correct for the dip of the interface from where the reflection occurred
b. To align reflection events so they can be stacked
c. To account for the different source-geophone separations
d. To convert the data to a common shot gather
38. The final seismic trace after processing is best thought of as
a. reflections from layers directly below a coincident source and receiver at
the surface
b. reflections from seismic waves that travel various paths in the earth
c. refracted arrivals due to layer interfaces
d. a direct representation of the local geology
39. Seismic velocity of materials depends upon the elastic moduli of the material. An
elastic modulus is the
a. amount of deformation before material breaks.
b. force needed to initiate S-wave or P-wave travel.
c. ratio of a particular stress to a resulting strain.
d. ratio of velocities of different types of waves.
40. The data recorded by a seismometer consists of
a. First break picks, which are time versus geophone position.
b. Records of ground motion for 10's to 100's of milliseconds following the
initial source energy.
c. Depths to refraction interfaces as a function of distance along a line.
d. Distance from shot to detector.
41. Acoustic impedance, involving _______, is a compound parameter that can be
used to describe the efficiency of seismic reflection and transmission.
a. velocity and density
b. critical angle and velocity
9. c. reflection and transmission coefficients
d. layer thickness and velocity
42. What is the minimum data set that can be interpreted to yield two depths for a 1-
interface model?
a. One shot into one end of a line of geophones.
b. Two shots; one at each end of the line.
c. One shot at each end of the line and one at it’s centre.
d. As many shots as it takes to get a refraction arrival at every geophone
from both directions.
43. If the layer is dipping instead of flat, the ITM (Intercept Time Method) approach
to interpretation is made a little more complicated because ...
a. The critical angle changes if the interface is dipping.
b. Dipping layers are “hidden” from refraction measurements.
c. Depths under each geophone are required in this case.
d. The second layer’s velocity is not obtainable directly from the slope of
refraction arrivals from one shot.
44. In a travel-time versus distance plot in seismic refraction, the slopes of the
segments depend on the _______.
a. change in seismic velocity at the boundary
b. seismic velocity in each layer
c. seismic velocity and dip in each layer
d. thickness of each layer
45. Two seismic refraction surveys have been done at two different sites, where the
basic geological models are all believed to be single horizontal layer plus
basement. The two time-offset plots have the same slope for direct arrival and
refracted arrival, but differ in the intercept time. The intercept time at Site A is
20ms while at Site B is 35ms, so what can be concluded?
a. Site A and Site B have exactly the same velocity model
b. the surface layer in Site B is thicker than that in Site A
c. the surface layer in Site A is thicker than that in Site B
d. not enough information to give any conclusion
46. A common midpoint gather refers to
a. seismic traces acquired from a single shot
b. seismic traces that are acquired with a constant source receiver separation
c. seismic traces that have been moveout corrected with respect to a central
geometrical location.
d. seismic traces that have a source and receiver symmetrically placed about
a single location.
10. 47. Prior to “stacking” the data must be
a. corrected for the normal moveout of the reflections
b. filtered to remove noise
c. converted to common shot gathers
d. all of these
48. Consider an earth composed of three layers and a basement and let 𝑟𝑖 denote the
reflection coefficient at the bottom of the i’th layer and let 𝑡𝑖 denote the
transmission coefficient at the bottom of the i’th layer. If the initial amplitude of
the seismic wave is unity, what is the amplitude of the wave that arrives at the
surface? :
a. 𝑟2(1 − 𝑟1
2
)
b. 𝑟2
c. 𝑟1𝑟2
d. 𝑟2𝑡1
49. A rural town needs a new source of water, and you are asked to map the water
table. Your goal is to detect the interface between a dry and saturated sand. What
would be the optimal seismic refraction experiment?
a. Dynamite source to generate strong ground roll
b. An air-gun to generate P-waves
c. Sledge hammer striking a plate vertically to generate P-waves
d. Sledge hammer striking a plate horizontally to generate S-waves
50. Assuming a positive impulse source, which of the following configurations will
likely give rise to the strongest negative (-) reflection? (Assume layer 2 below
layer 1)
a. 𝑣1 > 𝑣2 & 𝜌1 < 𝜌2
b. 𝑣1 < 𝑣2 & 𝜌1 < 𝜌2
c. 𝑣1 < 𝑣2 & 𝜌1 > 𝜌2
d. 𝑣1 > 𝑣2 & 𝜌1 > 𝜌2
51. Assume a layered Earth with increasing impedance as a function of depth
(𝒁𝟏 < 𝒁𝟐 < 𝒁𝟑 < 𝒁𝟒 ), layer 4 is assumed to be infinite in depth (halfspace). If
you were to increase the impedance of layer 4 (𝒁𝟒 ), which of the following
statements is true:
a. The reflectivity of the first and second interface would not change.
b. Only the reflectivity of the first interface would not change.
c. The transmission coefficient at the base of the third layer would not
change since 𝒁𝟒 is a halfspace.
d. The change will give rise to a negative reflection measurable at surface
11. Short Answer Questions
For the next question you will need to use the seismic section shown below. Note the
units for the x-axis is meters and for y-axis is milliseconds.
Assume that the geology is adequately represented as uniform layer of contant thickness
overlying a halfspace.
a. What is the velocity of the upper layer?
b. What is the velocity of the layer below (that is, the halfspace)?
c. What is the thickness of the top layer?
d. What are the linear features arriving at (x=25m, t=200ms) and (x=5-10m,
t=200ms)?
12. 52. (8 pts) Consider the two plots below
(i) P-wave (ii) SH-wave
a. (2 pts) What source is used for generating a P-wave refraction
experiment? What source is used for generating an SH refraction?
b. (2 pts) In plot (i) what is meant by the air wave? Why is it not seen in plot
(ii)?
c. (3 pts) What is the thickness of the top layer that can be obtained directly
for the SH reflection seen in (ii). Show your work.
d. (1 pt) How would you determine if the refracted P and S waves were, or
were not, coming from the same interface.
53. (12 pts) Consider the three layer earth described below. All layers have the same
density.
13. a. (2 pts.) We’re interested in the seismogram that would be obtained at zero
offset. Consider the reflection from the top of layer 2: What is the travel
time for that reflection event and what is the value of the reflection
coefficient?
b. (2 pts) Consider the reflection from the top of layer 3. What is the travel
time for that reflection event and what is the value of the reflection
coefficient?
c. (2 pts) Compute the transmission coefficients associated with waves that
travel through the first interface; that is, the transmission coefficients for
the downward and upward travelling waves.
d. (1 pt) Plot the final reflectivity log as a function of time. Make sure you
provide the amplitude of each event.
e. (2 pts) Now consider the refracted wave along the first interface: What is
the shortest offset you could measure the refracted wave?
f. (1 pt) Why would you not expect refraction before this offset?
g. (2 pts) Where would the refracted wave overtake the direct arrival?
54. (5 pts) A seismic refraction survey was carried out to find the depth and dip of a
bedrock interface. Forward and reverse shots were used and the travel time plots
are provided below:
a. (3 pts) Using the plot above, estimate the velocity of the upper layer as
well as the up and down dip velocities of the second layer.
b. (2 pts) Which way is the layer dipping? Show how you arrived at your
answer.
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
Distance (m)
Time
(s)
14. 55. (3 pts) Sketch the motion of a particle due to three different wave types: P, SH
and SV waves (3 drawings)
56. (4 pts) Your team completed their first day of seismic refraction survey over a
flat-layered Earth. You constantly start measuring the refracted wave as first
arrival for receiver offsets > 25 m. You would like optimize your next day of
survey by increasing the offset between the source and the first receiver.
Assuming that the geophone spacing is fixed a 5 m, and the closest distance from
the source you can measure is also 5 m:
a. What would be largest distance between the source and your fist geophone
in order to measure velocity of the first layer?
b. Why would want to increase the source-receiver array separation?
57. The plot below shows ray paths and arrival times for P-wave seismic signals
recorded at a geophone located 60m from a source.
a. Using the plots below, what can you deduce about the relationship
between the velocities of each of the layers?
15. b. Imagine you can extend the spread of geophone to some large offset. From
your answer above, would you expect to see the refracted wave along
layers as first arrival?
58. The normal incidence trace below (right) was generated from the noisy data on
the right.
a. What is a CMP gather? Using a geologic model consisting of a single
layer over a half-space, sketch 3 ray-paths to support your explanation.
b. There are two main processing steps used to obtain a single seismic trace
from the noisy CMP gather. Name and describe these two steps.
59. You have a geologic model consisting of 3 layers with seismic velocities v1, v2,
v3, and thicknesses h1, h2, and h3, where h3 ∞
a. Describe a scenario where second layer may not be detected using
refraction seismic.
b. Describe a scenario where second layer may not be detected using
reflection seismic.
16. 60. To aid in performing an NMO correction to the noisy seismic data on the left, the
semblance plot on the right was generated.
a. Describe what a semblance analysis does (you may want to use a sketch
on the CMP gather to explain)?
b. Using theses plots, approximately what intercept time and stacking
velocity would you use to perform the NMO correction?